Pearls & Oy-sters: Isolated Acquired Amusia in a Patient With Right Temporal Stroke

Strokes in the right temporal lobe are known to cause acquired amusia, or deficits in music processing, which can be formally assessed using the online version of the Montreal Battery of Evaluation of Amusia (MBEA). Patients with acquired amusia most often present with not only amusia but also other neurologic symptoms, such as aphasia, neglect, or memory issues. We report a case of a 39-year-old man who initially presented for follow-up after a single seizure episode. Two years before the seizure, the patient experienced an episode of headache, nausea, and vomiting, after which he developed difficulty appreciating music and carrying a tune, something he had never experienced before as a competent trumpet player and singer. An MRI scan performed after his seizure revealed encephalomalacia and gliosis within the right lateral temporal lobe with areas of hemosiderin deposition, suggesting that the episode 2 years ago was a stroke. His standard neurologic examination was normal including a score of 30/30 on the Montreal Cognitive Assessment. On the online version of the MBEA, he scored 66.7% on the off-tune test, 87.5% on the off-beat test, and 70.8% on the out-of-key test, consistent with a diagnosis of amusia. This case highlights the importance of eliciting less common isolated neurologic symptoms in patients with an otherwise normal examination, including musical symptoms. We also highlight the utility of tools such as the MBEA to document the severity of amusia and potentially to follow patients' progress as they recover.